Finding the Fourth Proportional to 2,878.64, 4,287.89 and 2,840.37

Step by Step Solution

1. Step 1: Write the proportion equation
   2,878.64 : 4,287.89 = 2,840.37 : x
2. Step 2: Convert to fraction form
   2,878.64/4,287.89 = 2,840.37/x
3. Step 3: Cross multiply
   2,878.64x = 4,287.89 × 2,840.37
4. Step 4: Simplify right side
   2,878.64x = 12,179,169.16
5. Step 5: Solve for x
   x = 12,179,169.16/2,878.64
6. Step 6: Final answer
   x = 4,230.88